Just wanted to add to the discussion.
Since 2011, I have run the Cradlepoint MBR-1200B and added their modem cap to it.
https://3gstore.com/product/3552_cradlepoint_4g_lte_modem_cap.html
You put your sim card in the modem cap, and plug that into the MBR1200B. I went this route because I wanted the most stable connection possible. Jetpacks were not an option yet, and I got tired of fighting with aircards plugged directly into my laptop. Going this route, I would have no compatibility issues from an aircard company sending out an update that no longer plays nice with something else, etc. The modem cap also has nice sturdy screw on antenna connections that allows me to have TWO hard wired external antennas that support MIMO (multiple input/multiple output) for faster data speeds. I have two roof mounted Maximum Signals super trucker antenna (9db gain). The icing on the cake is that the modem cap has a higher power transmitter. I can't remember the figures, but it transmits slightly lower power than the highest power stand alone cellular amps. I tried adding two cellular amps (one for each antenna), to get that last little bit of power, but I kept blowing the input stage of the amps since the Cradlepoint modem cap was already sending a hot signal. I use the Verizon modem cap, and have an AT&T aircard feeding the second connection on the router which gives me automatic fall back in case Verizon isn't serving an area.
It was a PITA at the time researching and putting it together, but it has been insanely rock solid. It is very common for me to be the only person with data in a group of cars. I plan to replace the roof mounted antennas when I get time.
Right now, I'm watching cellular bonding mature to bring down the prices and will move into that at some point.
@Dan Robinson , I have a brand new never opened Cradlepoint MRB95 that I will sell you for $100 plus shipping. It would come with the "good guy" guarantee. If you have a problem with it in the first year, just call me and I'll PayPal all your money back to you. I would rather have your friendship than the $100. It is in its original box, how it was shipped to me.